Tactile display device and method of controlling tactile display device

ABSTRACT

In a tactile display apparatus which displays image information as differences in elevation created among tactile pins which are disposed crisscross in a matrix arrangement, a fewer number of solenoids are used which make the tactile pins project and retract, the number of components is accordingly reduced and the crisscross adjacent gaps between the tactile pins are narrow. Since the solenoids  4  which make the tactile pins  10  project and retract are disposed in a row vertically, one for every preset number of the tactile pins which are lined up in the vertical direction, to a movable unit  5  which is capable of freely moving in the vertical direction and the horizontal direction along which the tactile pins are disposed, and since the movable unit repeatedly moves along the vertical direction and the horizontal direction in turn, the solenoids make all tactile pins project and retract.

This application is the national stage of PCT/JP03/05614, filed May 2,2003 which claims priority from JP2002-132627, filed May 8, 2002, thedisclosures of both documents being incorporated herein in theirentireties by reference thereto.

FIELD OF THE INVENTION

The invention belongs to the technical field of a tactile displayapparatus which one touches by hand to recognize screen information anda control method for the tactile display apparatus.

BACKGROUND ART

A tactile display apparatus having a structure which permits a visuallyhandicapped person to recognize image information, such as a photograph,a graphic and/or a letter, by means of his/her (for the remainder of theapplication the male pronoun will be generically used for males andfemales) tactile sense at his fingertips has been proposed in recentyears. Known as such an apparatus is one in which pins which are capableof freely projecting or retracting are disposed like a matrix on adisplay board portion, and as the pins are controlled to project andretract, a difference in elevation appears among the pins. Thereby, avisually handicapped person feels and senses the difference in elevationwith his hand and recognizes image information, as described in JapanesePublished Unexamined Patent Application No. 2000-221872 for instance. Ina structure of such an apparatus, each one of the pins is controlled toproject or retract by an actuator, such as a solenoid (electromagnet) orthe like, corresponding to each such pin.

SUMMARY OF THE INVENTION

However, in the conventional apparatus described above, all pins aremade to project or retract by corresponding solenoids. Hence, theadjacent gaps between the pins cannot be as narrow as or narrower thanthe widths of the solenoids. This not only increases the gaps betweenthe pins and makes it hard to display a fine image, but also leads to aproblem where the larger the number of pins is, the larger the number ofcomponents, including solenoids, required and the control and managementof the increased number of solenoids becomes complex. These are theproblems to be solved by the invention.

The invention has been made to solve the problems defined above. Theinvention provides a tactile display apparatus in which tactile pinsdisposed in a matrix arrangement on a display board portion are capableof freely projecting or retracting and information such as an image isdisplayed in accordance with concavities and convexities formed as thetactile pins project or retract, comprising a movable unit which iscapable of freely moving in the vertical direction and the horizontaldirection relative to the display board portion; actuators disposed atthe movable unit so as to control projecting or retracting of eachtactile pin of the tactile pins; a control part which controls drivingof the actuators in accordance with an information signal, such as animage input, from outside; and movement mechanisms which move themovable unit in the vertical direction and the horizontal direction.This substantially reduces the number of actuators required to controlprojecting or retracting of the tactile pins, and hence, the number ofcomponents.

The actuators which control projecting or retracting of the tactile pinsmay be provided to the movable unit so as to be disposed in a verticalrow and/or horizontal row, one for every preset number of the tactilepins lined up in the vertical direction and/or the horizontal direction,in which case, because this permits setting the adjacent gaps betweenthe tactile pins narrowly without any restriction imposed upon theactuators, it is possible to even display fine information, such as animage, on the display board portion and obtain a sharp tactile displayhaving a high resolution.

The display board portion may be formed by an upper plate and a lowerplate, a pin holding member which is like a sheet firmly held airtightlybetween the upper plate and the lower plate, and the tactile pinspenetrating and supported in through holes which are formed in a matrixarrangement in the upper plate and the lower plate and the pin holdingmember. This makes it possible to maintain the pin holding members in astate of tension, hold the tactile pins securely at projecting positionsor retracting positions, and finish the display board portion like acompact kit which is thin between the top and the bottom.

When the pin holding member is formed by cloth, such as denim which hasfriction force, it is possible to securely hold the tactile pins andapply appropriate frictional force which will not hinder the projectingor retracting movements of the tactile pins.

The display board portion may be attached to a top surface portion of acase body of the tactile display apparatus in such a manner that thedisplay board portion by itself can be freely attached to and detachedfrom the case body from outside, in which case it is easy to attach anddetach the display board portion, thus contributing to an improvement inthe ease of assembling and maintainability.

Further, tactile pins are formed by attaching tactile dot parts, whichare formed by spring pins, to the tip ends of main pin parts. Hence, thetactile pins are easily assembled and resistant to vibrations. Thetactile pins allow the differences in elevation to be recognized andidentified easily.

The actuation pins which move forward and backward as the actuatorsoperate may be disposed at the movable unit. The tactile pins mayprotrude as the actuation pins move forward, the actuation pins may moveaway from the tactile pins when retracting, and the actuation pins maymove forward and backward while the movable unit moves. Hence, it ispossible to continuously and efficiently control projecting orretracting of the tactile pins.

The movable unit moves while avoiding any contact or connection with thedisplay board portion except for the actuation pins contacting thetactile pins. The movable unit can therefore move vertically andhorizontally at a high speed.

The movable unit is supported for free vertical movement via a verticalmovement mechanism by a cradle which is supported for free horizontalmovement via a horizontal movement mechanism by the case body of thetactile display apparatus. The movable unit can therefore movevertically and horizontally in a smooth manner.

The movable unit moves horizontally beyond the range in which theactuators control projecting or retracting of the tactile pins, and themovable unit moves vertically while moving horizontally beyond the rangein which projecting or retracting of the tactile pins is controlled.Hence, even when the timing of vertical movements is not set strictly,the movable unit can move horizontally and vertically in turn in asmooth fashion.

Further, the vertical movement mechanism of the movable unit may beformed by an actuating member which moves horizontally as one unit withthe movable unit, a fixed member which is fixed to the case body of thetactile display apparatus, and a one-way clutch mechanism which movesthe movable unit vertically as the actuating member moving horizontallyinterferes with the fixed member.

In this case, the fixed member may be disposed at both ends of the rangein which the movable unit moves horizontally. The movable unit is causedto move vertically during interference of the actuating member with thefixed member which is caused as the movable unit moves horizontallytoward one side, whereas the movable unit does not move verticallyduring interference of the actuating member with the fixed member whichis caused as the movable unit moves horizontally toward the other side.

The invention also provides for a control method for a tactile displayapparatus in which tactile pins disposed in a matrix arrangement on adisplay board portion are capable of freely projecting or retracting andinformation, such as an image, is displayed in accordance withconcavities and convexities formed as the tactile pins project orretract, comprising a movable unit which is capable of freely moving inthe vertical direction and the horizontal direction relative to thedisplay board portion; actuators disposed at the movable unit so as tocontrol projecting or retracting of the tactile pins; a control partwhich controls the driving of the actuators in accordance with aninformation signal, such as an image, received from outside; movementmechanisms which move the movable unit in the vertical direction and thehorizontal direction, in the tactile display apparatus; and an externalcontrol part for outputting information signals, such as an image, tothe tactile display apparatus, the external control part pixelatinginformation fed to the external control part into the respective pixelsin accordance with the number of tactile pins which are disposed,binarizing the respective pixels so that the pixels will correspond tothe projecting or retracting of the tactile pins, sorting thus binarizedsignals in the order of driving the actuators, and outputting thusbinarized signals. This makes it possible to precisely display, usingdifferences in elevation among the tactile pins, image information fedto the external control part.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the drawings, inwhich:

FIG. 1 is a schematic diagram of a tactile display apparatus and a hostcomputer;

FIG. 2 is a plan view which shows the inside of a case of the tactiledisplay apparatus, except for a certain portion;

FIG. 3 is a front view which shows the inside of the case of the tactiledisplay apparatus, except for a certain portion;

FIG. 4 is a partially expanded drawing of FIG. 3;

FIG. 5 is a diagram for describing movements of tactile pins upward anddownward;

FIG. 6 is a side view of a portion where solenoids are disposed;

FIGS. 7(A), 7(B), 7(C), 7(D) and 7(E) are explanatory operation diagramsof a movable unit;

FIG. 8 is a side view of a portion where a motor is disposed;

FIG. 9 is a side view of a portion where a rotation axis is disposed;

FIG. 10 is a drawing which shows actuation of a vertical movementmechanism while the movable unit moves to the left;

FIG. 11 is a drawing which shows actuation of the vertical movementmechanism while the movable unit moves to the right; and

FIG. 12 is a drawing which shows ratchet arms as they are reset.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

An exemplary embodiment of the invention will now be described withreference to the drawings. In the drawings, 1 denotes a tactile displayapparatus (FIG. 1) which displays, as differences in elevation, imageinformation such as a photograph, a graphic and/or a letter output froma host computer (which corresponds to the external control part of theinvention) PC so that a visually handicapped person can recognize theimage with his tactile sense at the fingertips. The tactile displayapparatus 1 comprises components, such as a case body 2 which defines ahull, a display board portion 3 which displays differences in,elevation, a movable unit 5 (FIG. 2) seating solenoids (which correspondto the actuators of the present invention) 4 (FIG. 3) which give rise todifferences in elevation on the display board portion 3, a horizontalmovement mechanism 6 which moves the movable unit 5 in the horizontaldirection and a vertical movement mechanism 7 (FIG. 2) which moves themovable unit 5 in the vertical direction, and a control part 8 (FIG. 3)which receives a signal from the host computer PC and outputs a controlcommand to the solenoids 4, the horizontal movement mechanism 6, thevertical movement mechanism 7, and the like based on the signal.

For the convenience of description, assuming that the tactile displayapparatus 1 is placed on a desk or the like, the front being the sidefacing a visually handicapped person who touches the display boardportion 3 will be hereinafter referred to as the front, the back as therear side, the left as the left-hand side, the right as the right-handside, the left/right direction as the horizontal direction and thefront/back direction as the vertical direction hereinafter. However, thevertical direction and the horizontal direction referred to in theinvention are not limited to the defined directions of course.

The case body 2 is shaped like a box having a top surface 2 a, a bottomsurface 2 b and side surfaces 2 c, 2 d, 2 e and 2 f on the front, theback, the left and the right (based on a point of view described above,i.e., as the visually impared person faces the display board portion 3).The top surface 2 a of the case body 2 has an opening 2 g which acceptsthe display board portion 3.

The display board portion 3 (FIG. 3) is comprised of a surface boardportion 9 which has a rectangular shape, tactile pins 10 which canproject beyond or retract from the top surface of the surface boardportion 9, and the like. The display board portion 3 is attached to andsupported by the case body 2 via support brackets 14 in a conditionwhere the top surface of the display board portion 3 protrudes upwardlybeyond the top surface 2 a of the case body 2. In this structure, thesupport brackets 14 comprise stepped portions 14 a (FIG. 6) projectinginward beyond the opening 2 g of the top surface 2 a of the case body,so that the display board portion 3 can be mounted to the case body 2 asscrews 14 b are inserted into the stepped portions 14 a from above thedisplay board portion 3 in a condition where the display board portion 3is on the top surface of the stepped portions 14 a. The display boardportion 3 is thus structured such that the display board portion 3 alonecan be freely attached and detached from outside the case body 2.

An upper plate 11 and a lower plate 12 and a friction member 13, whichis like a thin film sheet firmly held in an airtight manner between theupper and the lower plates 11, 12, are in a laminated manner andassembled into one, whereby the surface board portion 9 forming thedisplay board portion 3 is obtained. A number of through holes 15 areformed in a matrix arrangement in the surface board portion 9,penetrating through the upper plate 11, the friction member 13, and thelower plate 12 in the vertical direction.

There are 48 such through holes in the vertical direction and 64 suchthrough holes in the horizontal direction, i.e., 48 rows and 64 columnsfor a total of 3072 such through holes 15 in this exemplary embodiment.Each through hole 15 accepts a tactile pin 10 in such a manner that thetactile pin 10 can move upward or downward as controlled. The tactilepin 10 (FIG. 5) is formed by a main pin part 10 a whose top end portionis cone-shaped, a tactile dot part 10 b which is fixedly engaged withthe top end of the main pin part 10 a, and is cylindrical and slightlylarger in diameter than the main pin part 10 a, and a disk-like abuttingpart 10 c whose bottom surface is arc-shaped and which is attached tothe bottom end of the main pin part 10 a. When actuation pins 16, whichwill be described later, push the abutting parts 10 c from below, thetactile pins 10 rise up to upper movable positions at which the top endportions of the tactile dot parts 10 b project upwardly beyond the topsurface of the surface board portion 9. Conversely, the tactile pins 10at the upper movable positions, when pushed down by a roller 17 (FIG. 1)which will be described later, move downwardly to lower movablepositions at which the top end portions of the tactile dot parts 10 bbecome approximately flush with the top surface of the surface boardportion 9. In this manner, the tactile pins 10 at the upper movablepositions and the lower movable positions form differences in elevation,which provides the image information on the display board portion 3.

The inner diameters of the through holes 15 are set such that thethrough hole portions formed in the upper plate 11 correspond to thediameters of the tactile dot parts 10 b of the tactile pins 10, and thethrough hole portions formed in the friction member 13 and the lowerplate 12 correspond to the diameters of the main pin parts 10 a of thetactile pins 10. The tactile pins 10 at the lower movable positions areblocked from moving further down when the bottom ends of the tactile dotparts 10 b contact the top surface of the friction member 13, and frommoving further upwardly when the top surfaces of the abutting parts 10 ccontact the bottom surface of the lower plate 12.

The friction member 13 is formed by a thin film sheet member, such asleather, rubber or cloth, and corresponds to the pin holding member ofthe invention. In this exemplary embodiment, the friction member 13 isformed by cloth, such as denim which has friction force. Firmly held inan airtight manner between the upper and the lower plates 10, 11, thefriction member 13 is held in a state of tension. The tactile pins 10 atthe upper movable positions and the lower movable positions are securelyand instantly held at these positions by the friction force of thefriction member 13. The friction force of the friction member 13 appliesa minimal and stable resistance to the tactile pins 10 but does notprevent the tactile pins 10 from moving upward or downward.

Further, the tactile dot parts 10 b are formed using spring pins(cylindrical pins having split grooves along the axial direction whichare elastic along the radius direction). Owing to the spring force ofthe spring pins, the tactile dot parts 10 b are engaged easily with themain pin parts 10 a without fail, to have securing strength againstvibrations. While the top end portions of the tactile dot parts 10 b areto be touched at the fingertips, the top end shoulder portions of thespring pins are square, i.e., the top and cylindrical side wall are atright angles to one another as seen from the side in FIG. 5. Thisprovides an advantage where a feeling for recognizing and identifyingthe boundaries between projecting sections is smooth and it is thereforeeasy to recognize the image information.

The roller 17 is for applying external force which moves the tactilepins 10 at the upper movable positions down to the lower movablepositions against the friction force of the friction member 13. Theroller is supported by the case body 2 such that the roller 17 canrotate on the surface board portion 9 during movement. Hence, as theroller 17 rotates to push down the tactile pins 10 which are at theupper movable position, the tactile pins 10 move down to the lowermovable position.

The movable unit 5 is housed within the case body 2 together with thehorizontal movement mechanism 6, the vertical movement mechanism 7 andthe control part 8. The movable unit 5 comprises eight solenoids 4, theactuation pins 16 which move upward and downward as the solenoids 4 turnon and off, a support frame 18 (FIG. 4) to which the solenoids 4 and theactuation pins 16 are attached, and the like. Although the movable unit5 is capable of moving in the horizontal direction and the verticaldirection below the display board portion 3 described above, the detailsof the horizontal and the vertical movement mechanisms 6, 7 will begiven later. Actuation of the actuation pins 16 in accordance withturning on and off of the solenoids 4, the arrangement of the solenoids4 and movements of the movable unit 5 in the horizontal direction andthe vertical direction will now be described.

The support frame 18 is obtained by assembling a top side 18 b, a middleside 18 c, and a bottom side 18 d to a main frame part 18 a as oneintegrated unit. The eight solenoids 4 are equidistantly disposedvertically in a row between the bottom side 18 d and the middle side 18c. A plunger 4 a of each solenoid 4 penetrates and protrudes upwardlybeyond the middle side 18 c, and is set so as to move upward when thesolenoid is ON and downward when the solenoid is OFF. The actuation pins16 penetrate through the top side 18 b and are accordingly supported bythe top side 18 b through the springs 19 such that the actuation pins 16are located above the plungers 4 a. Plunger receiving parts 16 a areformed as integrated, lower sections of the actuation pins 16.

When the solenoids 4 are OFF, the plungers 4 a which are moved down, orretracted, do not push the actuation pins 16. In this condition, the topends of the actuation pins 16 are slightly away from the abutting parts10 c of the tactile pins 10 which are at the lower movable positionsdescribed above.

On the other hand, when the solenoids 4 are ON, the plungers 4 a move upto push the plunger receiving parts 16 a of the actuation pins 16 frombelow thereby moving the actuation pins 16 upward. The actuation pins 16which have thus moved upward push the abutting parts 10 c of the tactilepins 10 from below, and the tactile pins 10 move to the upper movablepositions as described above.

The solenoids 4 used have small inertia. The control part 8 controls theturning on and off of the solenoids 4 is described later. To improve astart-up characteristic of the solenoids 4, a capacitor whichcompensates for a voltage drop is used in an output circuit of thecontrol part 8. Further, when the actuation pins 16, which have movedupward, are to be moved downward, the solenoids 4 are switched from ONto OFF immediately before the plungers 4 a arrive at the top endpositions and the repulsive force and the spring force of the springs 19move the actuation pins 16 down. Thus, the actuation pins 16 can quicklymove downward. The actuation pins 16, treated with hard alumite, arelight yet ensure necessary hardness. The actuation pins 16 move upwardor downward at a high speed in this manner as the plungers 4 a of thesolenoids 4 move upward or downward. Therefore, the actuation pins 16can move up or down smoothly while the movable unit 5 moves horizontallyas described later in detail. In addition, the movable unit 5 will notcontact or become connected (linked, engaged) with the display boardportion 3 except for pushing of the abutting parts 10 c of the tactilepins 10 by the actuation pins 16, which allows movement of the movableunit 5 in the horizontal direction and the vertical direction at a highspeed which will be described later.

Eight of the actuation pins 16 are equidistantly disposed in thevertical direction in a single row. Thus, the actuation pins 16 cantherefore respond to the respective solenoids 4. The interval betweenadjacent actuation pins 16 is one actuation pin 16 is disposed for everysix, i.e. with five intervening, tactile pins 10 which are disposed inthe vertical direction in the display board portion 3.

In other words, when the movable unit 5 is located at the origin, asshown in the explanatory operation diagram of FIG. 7(A), the firstactuation pin 16 is at a location which corresponds to the first tactilepin 10 in the first column, the second actuation pin 16 is at a locationwhich corresponds to the seventh tactile pin 10 in the first column, andthe n-th actuation pin 16 (n=1 through 8) is at a location whichcorresponds to the {(n−1)×6+1}-th tactile pin 10 in the first column.

In the explanatory operation diagrams in FIGS. 7(A)-7(E), the right-mostcolumn is the first column, the columns arranged to the left are thesecond, the third and subsequent columns, and the left-most column isthe 64-th column. The bottom row is the first row, the rows above arethe second, the third and subsequent rows, and the top row is the 48-throw. Further, although the actuation pins 16 can move horizontallybeyond the tactile pins 10 which are in the first and the 64-th columnsas described later, for the purpose of description below, the range ofhorizontal movements of the actuation pins 16 will be from the first tothe 64-th columns of the tactile pins 10.

In response to a start-up command from the control part 8, the movableunit 5 located at the origin moves horizontally toward the left-handside from the first column of the tactile pins 10 to the 64-th column ofthe tactile pins 10 as shown in FIG. 7(B). After the actuation pins 16have arrived at the 64-th column of the tactile pins 10, the movableunit 5 moves vertically for one row at the back of the tactile pins 10as shown in FIG. 7(C). As a result, the first actuation pin 16 is at thelocation which corresponds to the tactile pins 10 in the second row, thesecond actuation pin 16 is at a location which corresponds to thetactile pins 10 in the eighth row, and the n-th actuation pin 16 (n=1through 8) is at a location which corresponds to the tactile pins 10 inthe {(n−1)×6+2}-th row. Following this, the movable unit 5 moveshorizontally toward the right-hand side from the 64-th column of thetactile pins 10 to the first column of the tactile pins 10 as shown inFIG. 7(D) after reaching the first column of the tactile pins 10, themovable unit 5 again moves vertically one row at the back of the tactilepins 10 as shown in FIG. 7(E). This horizontal and vertical movement isrepeated for three reciprocal movements in the horizontal direction,whereby eight actuation pins 16 are located at locations whichcorrespond to all 3072 tactile pins 10. Thus, the eight solenoids 4 canmove all tactile pins 10 upward as required by the image data.

With respect to the horizontal movement mechanism 6 which moves themovable unit 5 in the horizontal direction, the movable unit 5 issupported by a first cradle 20 (FIG. 6) which will be described later insuch a manner that the movable unit 5 can move vertically but nothorizontally and therefore the movable unit 5 moves together with thefirst cradle 20 in the horizontal direction when the first cradle 20moves in the horizontal direction. Horizontal movements of the firstcradle 20 will now be described.

Horizontal guide members 21, 21 a elongated in the left/right direction(in FIG. 6, the right side of the figure is the back of the tactiledisplay apparatus 1) are fixed to the front and the back end portions ofthe first cradle 20. Meanwhile, the side surfaces 2 c, 2 d on the frontand the back of the case body 2 mount, through support members 23,horizontal rails 22, 22 a elongated in the left/right direction. Thehorizontal rails 22, 22 a at the front and the back receive, viabearings 24, the front and the back horizontal guide members 21, 21 a insuch a manner that the horizontal guide members 21, 21 a can freely movealong the left/right direction (horizontal direction).

A motor 25 (FIG. 8) is disposed in a back right portion inside the casebody 2. Rotational drive in the forward and the backward directions ofthe motor 25 is output at an output axis 25 b via a decelerator part 25a. A drive pulley 26 is fixed to the output axis 25 b as an integratedpart. A rotation shaft 27 (FIG. 9) is supported for free axial rotationsat the left end portions of the front and back side surfaces 2 c, 2 d ofthe case body 2. First and second driven pulleys 28, 29 are fixed to therotation shaft 27 at the front and the back end portions as integratedparts. Further, a spindle 30 (FIG. 8) is axially received by aright-hand portion of the front side surface 2 c of the case body 2 at alocation which is coaxial with the output axis 25 b, and a third drivenpulley 31 is axially disposed to freely rotate on the spindle 30.

A drive belt 32 runs between the drive pulley 26 and the second drivenpulley 29, and a driven belt 33 runs between the first driven pulley 28and the third driven pulley 30. The front and the back end portions ofthe first cradle 20 are fixed to and integrated with the drive belt 32and the driven belt 33, respectively, via retainer members 34 (FIG. 6).

Rotational drive in the forward and the backward directions of the motor25 is transmitted to the drive pulley 26 from the output axis 25 b,moving the drive belt 32 in the left/right direction, and furthertransmitted from the second driven pulley 29 to the first driven pulley28 via the rotation shaft 27, moving the driven belt 33 in theleft/right direction, and as the drive belt 32 and the driven belt 33move in the left/right direction, the first cradle 20 moves in theleft/right direction.

While the front and the back horizontal guide members 21, 21 a,elongated in the left/right direction, are fixed to the front and theback ends of the first cradle 20 as described above, a second cradle 35(FIGS. 2 and 3) is fixed to the front and the back horizontal guidemembers 21, 21 a. In short, the first and the second cradles 20, 35 arelinked as one integrated unit via the front and the back horizontalguide members 21, 21 a, and hence, as the first cradle 20 describedabove moves in the left/right direction, the second cradle 35 also movesin the left/right direction.

A linear plate 36 elongated in the left/right direction is attached asone integrated unit to the second cradle 35. The linear plate 36 has 64comb-like grooves 36 a, which correspond to the horizontal arrangementof the tactile pins 10, lined up in the horizontal direction of thelinear plate 36. On the other hand, the bottom surface 2 d of the casebody 2 seats first through fourth photosensors 37-40 (FIG. 2) which havelight emitting elements and light receiving elements for detection ofthe location of the linear plate 36.

As the first to fourth photosensors 37-40 detect the location of thelinear plate 36, the location of the movable unit 5 which moves in theleft/right direction together with the linear plate 36 is detected. Inother words, when the first photosensor 37 detects the right-mostposition of the linear plate 36, it detects the movable unit 5 has cometo the stop position. When the second photosensor 38 detects theright-most position of the linear plate 36, a right-hand side reverseposition is detected at which the movement of the movable unit 5 isreversed from the rightward movement to the leftward movement. The thirdphotosensor 39 detects the locations of the comb-like grooves 36 a ofthe linear plate 36, thereby sensing the timing to turn the solenoids 4on, namely, the timing at which the actuation pins 16 are to move thetactile pins 10 upward. The fourth photosensor 40 is set so as to detectthe left-most position of the linear plate 36, to thereby detect aleft-hand side reverse position at which the movement of the movableunit 5 is reversed from the leftward movement to the rightward movement.

The second cradle 35 is mounted to the control part 8, and the controlpart 8 is formed using a general-purpose control unit, such as a PLC.Based on an output signal from the host computer PC, detection signalsfrom the first to the fourth photosensors 37-40, etc., the control part8 outputs control commands to the motor 25, the solenoids 4, etc.,thereby controlling the motor 25 to drive forward or backward or tostop, the solenoids 4 to turn on or off, etc.

With respect to the vertical movement mechanism 7 which moves themovable unit 5 in the vertical direction (front/back direction), theeight solenoids 4 and the actuation pins 16 are attached to andsupported by the support frame 18 in the movable unit 5 as describedabove, and when the support frame 18 moves vertically relative to thefirst cradle 20, the movable unit 5 moves in the vertical direction.

That is, a guide member 41 (FIG. 4), elongated in the front/backdirection, is fixed to the main frame part 18 a of the support frame 18.Meanwhile, the first cradle 20 seats a vertical rail 42 elongating inthe front/back direction, and the guide member 41 is engaged with thevertical rail 42 via a bearing 43 such that the guide member 41 can movefreely in the front/back direction (vertical direction).

A rack 44, elongated in the front/back direction, is fixed to the bottomside 18 d of the support frame 18. Ratchet gear teeth 44 c (FIG. 10) areformed in front and back gear portions 44 a, 44 b of the rack 44. Inaddition, a spring (not shown) which urges the rack 44 toward the frontis linked to the rack 44.

A third cradle 45 (FIGS. 3, 4, and 10) is fixedly attached below thesecond cradle 35 with a gap therebetween. The third cradle 45 and thefirst cradle 20 are linked as one integrated unit via the front and theback horizontal guide members 21, 21 a and the second cradle 35. Hence,when the first cradle 20, described above, moves in the left/rightdirection, the third cradle 45 also moves in the left/right direction asone integrated unit.

A swing plate 46 is axially supported, via a pin axis 47 for freepivoting, by the third cradle 45. The swing plate 46 axially supports,via a pin axis 49, a front ratchet arm 48 for free pivoting. A fixedplate 50 is fixed to the third cradle 45. The fixed plate 50 axiallysupports, via a pin axis 52, a back ratchet arm 51 for free pivoting.Backstop parts 48 a, 51 a, which can freely fit with and leave ratchetgear teeth 44 c of the front and the back gear portions 44 a, 44 b ofthe rack 44, are formed at the top ends of the front ratchet arm 48 andthe back ratchet arm 51. The front ratchet arm 48 and the back ratchetarm 51 are always urged by the urging force of springs 53, 54 in thedirection in which the backstop parts 48 a, 51 a engage with the ratchetgear teeth 44 c (the counter-clockwise direction in FIGS. 10 and 11).When the backstop parts 48 a, 51 a are fit with the ratchet gear teeth44 c, the rack 44 can move toward the back but not toward the front,thereby realizing the one-way clutch mechanism of the invention.Stoppers 55, 56 are provided for the front ratchet arm 48 and the backratchet arm 51.

Further, the swing plate 46 is set such that it swings between anon-swing position at which it becomes approximately parallel to thefixed plate 50 and a swing position at which it has swung clockwise fromthe non-swing position. The swing plate 46 is always urged toward thenon-swing position by the urging force of a spring not shown.

Still further, the third cradle 45 axially supports a back portion of anactuation lever 57 via a pin axis 58 for free swinging. A pressingportion 57 a which contacts the swing plate 46 is formed on theleft-hand side of the actuation lever 57 as a boundary of the pin axis58 while a notched portion 57 b which is notched in a direction awayfrom the swing plate 46 is formed on the right-hand side of theactuation lever 57 as a boundary of the pin axis 58. In addition, anactuation projection 59 is disposed at the front end of the actuationlever 57, projecting downward.

A left-hand side dog 60 and a right-hand side dog 61 which are attachedto the bottom surface 2 b of the case body 2. The dogs 60, 61, whenviewed in plan view, look like triangles whose vertexes 60 a, 61 a arecentral portions along the left/right direction. The dogs 60, 61 are setsuch that they interfere with the actuation projection 59, which movesin the left/right direction as the third cradle 45 moves in theleft/right direction, and make the actuation projection 59 swing.Actuation of the actuation lever 57 will now be described.

First, as shown in FIG. 10, when the actuation projection 59 movingtoward the left-hand side abuts with the dogs 60, 61 from the right-handside, the actuation lever 57 swings counter-clockwise, and therefore,the actuation projection 59 moves over the vertexes 60 a, 61 a of thedogs 60, 61. At this stage, because the notched portion 57 b of theactuation lever 57, swung counter-clockwise, is faced with the swingplate 46, the actuation lever 57 will not act upon the swing plate 46and the swing plate 46 is held at the non-swing position.

On the contrary, as shown in FIG. 11, when the actuation projection 59moving toward the right-hand side abuts with the dogs 60, 61 from theleft-hand side, the actuation lever 57 swings clockwise. Therefore, theactuation projection 59 moves over the vertexes 60 a, 61 a of the dogs60, 61. At this stage, the pressing portion 57 a of the actuation lever57 is swung clockwise to push the swing plate 46 and make the swingplate 46 swing at the swing position. As the swing plate 46 thus swings,the front ratchet arm 48 engaged with the ratchet gear teeth 44 c of thefront gear portion 44 a of the rack 44 feeds the rack 44 one tooth.

When the actuation projection 59, moving toward the left-hand side,passes over the dogs 60, 61, the swing plate 46 does not swing and therack 44 therefore does not move vertically. Meanwhile, when theactuation projection 59, moving toward the right-hand side passes overthe dogs 60, 61, the rack 44 moves toward the back by one tooth and themovable unit 5 moves vertically toward the back together with the rack44 as one unit. The amount of movement is set the same as one gapbetween the rows of the tactile pins 10 described earlier.

An abut member for reset 62 (FIG. 12) is attached to the bottom surface2 b of the case body 2. The abut member for reset 62 is set such thatwhen the movable unit 5 has moved toward the right-hand side to a stopposition which will be described later, the abut member for reset 62abuts with the front ratchet arm 48 and the back ratchet arm 51 and theratchet arms 48, 51 swing clockwise. As the ratchet arms 48, 51 swingclockwise, the backstop parts 48 a, 51 a and the ratchet gear teeth 44 care reset, i.e., become disengaged from each other, the rack 44 isallowed to move toward the front, and the rack 44 moves toward the frontwhen urged by the spring (FIG. 12).

A description will now be given about horizontal movements (movementsalong the left/right direction) and vertical movements (movements alongthe front/back direction) of the movable unit 5 and a relationshipbetween the first to the fourth photosensors 37 through 40, theleft-hand side and the right-hand side dogs 60, 61 and the abut memberfor reset 62.

First, before the motor 25 starts moving, the front and the back ratchetarms 48, 51 abut with the abut member for reset 62, and the backstopparts 48 a, 51 a and the ratchet gear teeth 44 c of the rack 44 arereset, i.e., are disengaged from each other. At this stage, the rack 44is located at the front-most position, and the movable unit 5 is setsuch that the n-th actuation pin 16 (n=1 through 8) comes to theright-hand side to the tactile pin 10 which is in the first column andthe {(n−1)×6+2}-th row when the rack 44 is at the front-most position.Meanwhile, the actuation projection 59 comes to the right-hand side ofthe right-hand side dog 61.

Next, as the control part 8 outputs a start-up command, the motor 25drives the movable unit 5 and the vertical movement mechanism 7 towardthe left-hand side. As this occurs, the front and the back ratchet arms48, 51 move away from the abut member for reset 62 and swingcounter-clockwise owing to the urging force of the springs 53, 54, andthe backstop parts 48 a, 51 a engage with the front-most ratchet gearteeth 44 c of the front and the back gear portions 44 a and 44 b.Further, before the actuation pins 16 reach the tactile pins 10belonging to the first column, the actuation projection 59 passes overthe right-hand side dog 61. On this occasion, because the actuationprojection 59 is moving toward the left-hand side, the movable unit 5does not move vertically. After the actuation projection 59 has passedover the right-hand side dog 61, the actuation pins 16 reach the tactilepins 10 belonging to the first column and move further to the left-handside toward the tactile pins 10 belonging to the 64-th column, duringwhich the third photosensor 39 detects the timing of turning on of thesolenoids. Based on the timing detection signal from the thirdphotosensor 39 and an image information signal from the host computerPC, an ON-command is fed to selected ones of the solenoids 4, theactuation pins 16 move upward and make the corresponding tactile pins 10move to the upper movable positions. As the actuation pins 16 passbeyond the tactile pins 10 belonging to the 64-th column, the actuationprojection 59 passes over the left-hand side dog 60. At that time,because the actuation projection 59 is moving toward the left-hand side,the movable unit 5 does not move vertically. After the actuationprojection 59 has passed over the left-hand side dog 60, the fourthphotosensor 40 detects the left-hand side reverse position and the motor25, after stopping once, drives to move the movable unit 5 toward theright-hand side.

As movement to the right-hand side starts, first, the actuationprojection 59 passes over the left-hand side dog 60. On this occasion,because the actuation projection 59 is moving toward the right-handside, the rack 44 moves to the back by one tooth. Therefore, the movableunit 5 moves one row at the back of the tactile pins 10. Consequently,the n-th actuation pin 16 comes to the right-hand side to the tactilepin 10 which is in the 64-th column and the {(n−1)×6+2}-th row. Afterthe actuation projection 59 has passed over the left-hand side dog 60,the actuation pins 16 reach the tactile pins 10 belonging to the 64-thcolumn and move further to the right toward the tactile pins 10belonging to the first column, during which the third photosensor 39detects the timing of turning on of the solenoids as in the case of themovement to the left-hand side described above and an ON-command is fedto selected ones of the solenoids 4. As the actuation pins 16 passbeyond the tactile pins 10 belonging to the first column, the actuationprojection 59 passes over the right-hand side dog 61. In this case,because the actuation projection 59 is moving toward the right-handside, the rack 44 moves to the back by one tooth. Therefore, the movableunit 5 moves one row at the back of the tactile pins 10. As a result,the n-th actuation pin 16 comes to the right-hand side to the tactilepin 10 which is in the first column and the {(n−1)×6+3}-th row. Afterthe actuation projection 59 has passed over the right-hand side dog 61,the second photosensor 38 detects the right-hand side reverse positionand the motor 25, after stopping once, drives to again move the movableunit 5 toward the left-hand side.

In a similar fashion, the movement toward the left-hand side and themovement toward the right-hand side of the movable unit 5 is repeatedfor three reciprocal movements. During the third movement toward theright-hand side, the motor 25 does not stop even when the secondphotosensor 38 detects the right-hand side reverse position and themovable unit 5 further moves toward the right-hand side. As the movableunit 5 further moves toward the right-hand side beyond the right-handside reverse position, the ratchet arms 48, 51 abut with the abut memberfor reset 62, the backstop parts 48 a 51 a and the ratchet gear teeth 44a of the rack 44 are reset, i.e., are disengaged from each other. Hence,the rack 44 moves toward the front and returns to the state as it wasbefore the motor started. In synchronization with this, the firstphotosensor 37 detects the stop position, the motor 25 stops and thehorizontal and vertical movement of the movable unit 5 end.

The control part 8 of the tactile display apparatus 1 controls turningon and off of the solenoids 4 based on a data signal from the hostcomputer PC, differences in elevation are created among the tactile pins10, and an image is displayed. Briefly with respect to control for thehost computer PC, first, the host computer PC receives image date, suchas a camera image or a scanner image, processes the received image datain an image processing module, and creates an image file (e.g., jpeg,bitmap).

This is followed by pixelating the data of the image file in accordancewith the arrangement of the tactile pins 10 of the tactile displayapparatus 1 described above, to thereby turn the data into a 64×48 grid.

To divide pixels thus treated by pixelation into convexes (correspondingto ON solenoids) and concaves (corresponding to OFF solenoids) on thedisplay board portion 3, binarization is executed with reference to athreshold value which has been determined in advance.

The binarized data are sorted in accordance with an order in which thesolenoids 4 of the tactile display apparatus 1 act upon the tactile pins10, and the 64×48=3072 pixels are divided into a few blocks and outputin a predetermined serial communication format (e.g., as ASC data) inthe block order, at a COM port, to the tactile display apparatus 1. Acontrol code is transmitted concurrently, for the purpose of control tostart up the display apparatus 1.

By means of the exemplary structure described above, the tactile displayapparatus 1 shows image information, such as a photograph, a graphicand/or a letter, as differences in elevation created among the tactilepins 10 which are disposed in a matrix arrangement. When a visuallyhandicapped person touches the display by hand, he can recognize theimage information. The solenoids 4 for controlling projecting orretracting of the tactile pins 10 are disposed at the movable unit 5which is capable of moving horizontally and vertically.

This greatly reduces the number of the solenoids 4 relative to the manytactile pins 10 which are disposed in a matrix arrangement, achieves areduction in the number of the components, shortens the assembling stepand contributes to cost reduction.

Further, a solenoid 4 is disposed in a row vertically with five tactilepins 10 spacing between adjacent solenoids 4, the tactile pins 10 alsodisposed in the vertical direction. As the movable unit 5 moves in thehorizontal direction and the vertical direction repeatedly, the tactilepins 10 are moved upward by the solenoids 4. Because this contributes toa reduction in the number of the solenoids 4 and allows setting theadjacent gaps between the tactile pins 10 narrowly without beingrestricted by the dimensions of the solenoids 4, it is possible tofinely display information, such as an image, and obtain a sharp tactilescreen at a high resolution. While the intervals between the solenoids 4are five tactile pins 10 between adjacent solenoids 4 in this exemplaryembodiment, the invention is not so limited and any desired number oftactile pins can be disposed between adjacent solenoids. Alternatively,the solenoids may be disposed in a row not only vertically but alsohorizontally or even in a plurality of rows.

In addition, while control of the projecting of the tactile pins 10 bythe solenoids 4 is achieved via the actuation pins 16, because theactuation pins 16 rise up and push up the tactile pins 10 to the uppermovable positions as the solenoids turn on but move down and leave thetactile pins 10 untouched when the solenoids turn off and because theupward movements of the actuation pins 16 takes place while the movableunit 5 moves, projecting and the subsequent retracting, using roller 17,of the tactile pins 10 is controlled continuously and efficiently.

Even further, because the movable unit 5 will not contact or becomeconnected with the display board portion 3 except for pushing of thetactile pins 10 by the actuation pins 16, the movable unit 5 movesvertically and horizontally at a high speed and data inputted from thehost computer PC is displayed quickly on the display board portion 3.

Because the movable unit 5 moves horizontally beyond the range in whichthe solenoids 4 move the tactile pins 10 upward and the movable unit 5moves vertically while moving in the horizontal direction beyond thisrange, the movable unit 5 can move in the vertical direction and thehorizontal direction in turn smoothly even when the timing of thevertical movement is not strictly set.

The display board portion 3, penetrated and supported by the tactilepins 10, is obtained by assembling the upper and the lower plates 11, 12and the friction member 13, which is like a sheet firmly held in anairtight manner between the upper and the lower plates 11, 12, in alaminated manner. This maintains the friction member 13 in a state oftension, securely holds the tactile pins 10 at the upper movablepositions and the lower movable positions, and finishes the displayboard portion 3 like a compact kit which is the item between the top andthe bottom.

Further, the display board portion 3 is attached to the case body 2 insuch a manner that the display board portion 3 alone can be freelyattached and detached from outside the case body 2. Hence, it is easy toattach and detach the display board portion 3, which contributes to animprovement in the ease of assembly and maintainability.

The tactile display apparatus allows a visually handicapped person torecognize image information, such as a photograph, a graphic and/or aletter, using his tactile sense at the fingertips. The apparatus isparticularly effective as the number of components is reduced, becausethe crisscross adjacent gaps are shortened without any restrictionimposed by actuators, the display board portion is compact, the ease ofassembly, maintainability and the like are improved, and imageinformation fed to the control part is accurately displayed asdifference in elevation among the tactile pins, etc.

1. A tactile display apparatus in which tactile pins disposed in amatrix arrangement on a display board portion are capable of freelyprojecting or retracting and information is displayed in accordance withconcavities and convexities formed as the tactile pins project orretract, comprising: a movable unit which is capable of freely moving inthe vertical direction and the horizontal direction relative to thedisplay board portion; actuators disposed at the movable unit so as tocontrol projected or retracted position of each tactile pin of thetactile pins; a control part which controls driving of the actuators inaccordance with an information signal; and movement mechanisms whichmove the movable unit in the vertical direction and the horizontaldirection, wherein the display board portion comprises an upper plateand a lower plate, a pin holding member which is like a sheet firmlyheld airtightly between the upper plate and the lower plate, and thetactile pins penetrating and supported in through holes which are formedin a matrix arrangement in the upper plate and the lower plate and thepin holding member.
 2. The tactile display apparatus according to claim1, wherein the actuators which control projected or retracted positionsof each tactile pin of the tactile pins are provided to the movable unitso as to be disposed in a vertical row and/or horizontal row, one forevery preset number of the tactile pins lined up in at least one of thevertical direction and the horizontal direction.
 3. (canceled)
 4. Thetactile display apparatus according to claim 1, wherein the pin holdingmember is formed by cloth which has a friction force.
 5. The tactiledisplay apparatus according to claim 1, wherein the display boardportion is attached to a top surface portion of a case body of thetactile display apparatus in such a manner that the display boardportion by itself can be freely attached to and detached from the casebody from outside.
 6. The tactile display apparatus according to claim1, wherein the tactile pins are formed by attaching tactile dot parts,which are formed by spring pins, to the tip end portions of main pinparts.
 7. The tactile display apparatus according to claim 1, whereinthe actuation pins which move forward or backward as the actuatorsoperate are disposed at said movable unit, the tactile pins protrude asthe actuation pins move forward, the actuation pins move away from thetactile pins when retracting, and the actuation pins move forward orbackward while the movable unit moves.
 8. The tactile display apparatusaccording to claim 7, wherein the movable unit moves while avoiding anycontact or connection with the display board portion except for theactuation pins contacting the tactile pins.
 9. The tactile displayapparatus according to claim 1, wherein the movable unit is supportedfor free vertical movements via a vertical movement mechanism by acradle which is supported for free horizontal movements via a horizontalmovement mechanism by the case body of the tactile display apparatus.10. The tactile display apparatus according to claim 1, wherein themovable unit moves horizontally beyond the range in which the actuatorscontrol the projected or retracted position of each tactile pin of saidtactile pins, and the movable unit moves vertically while movinghorizontally beyond the range in which the projected or retractedpositions of the tactile pins are controlled.
 11. The tactile displayapparatus according to claim 1, wherein the vertical movement mechanismof the movable unit comprises an actuating member which moveshorizontally and integrally with the movable unit, a fixed member whichis fixed to the case body side of the tactile display apparatus, and aone-way clutch mechanism which moves the movable unit vertically inassociation with interference of the actuating member movinghorizontally with the fixed member.
 12. The tactile display apparatusaccording to claim 11, wherein the fixed member is disposed at the bothend sides of the range in which the movable unit moves horizontally, themovable unit is caused to move vertically in association withinterference of the actuating member with the fixed member which iscaused as the movable unit moves horizontally toward one side, whereasthe movable unit does not move vertically during interference of theactuating member with the fixed member which is caused as the movableunit moves horizontally toward the other side.
 13. (canceled)
 14. Acontrol method for a tactile display apparatus in which tactile pins areon a display board portion, using a movable unit mounting actuatorsthereon, a control part, and movement mechanisms to move the movableunit, the display board portion having an upper plate, a lower plate,and a pin holding member, the tactile pins penetrating and supported inthrough holes in the upper plate, the lower plate and the pin holdingmember, the method comprising: inputting image information; developingpixel information from the image information in accordance with thenumber of tactile pins; binarizing the pixel data into on/off data;driving the movable unit to move both horizontally and vertically;driving the actuators based on the binarized pixel data to raiseappropriate tactile pins, whereby an image is displayed as concavitiesand convexities on the display board portion.
 15. The tactile displayapparatus according to claim 4, wherein the display board portion isattached to a top surface portion of a case body of the tactile displayapparatus in such a manner that the display board portion by itself canbe freely attached to and detached from the case body from outside. 16.The tactile display apparatus according to claim 5, wherein the tactilepins are formed by attaching tactile dot parts, which are formed byspring pins, to the tip end portions of main pin parts.
 17. The tactiledisplay apparatus according to claim 6, wherein the actuation pins whichmove forward or backward as the actuators operate are disposed at saidmovable unit, the tactile pins protrude as the actuation pins moveforward, the actuation pins move away from the tactile pins whenretracting, and the actuation pins move forward or backward while themovable unit moves.
 18. The tactile display apparatus according to claim8, wherein the movable unit is supported for free vertical movements viaa vertical movement mechanism by a cradle which is supported for freehorizontal movements via a horizontal movement mechanism by the casebody of the tactile display apparatus.
 19. The tactile display apparatusaccording to claim 9, wherein the movable unit moves horizontally beyondthe range in which the actuators control the projected or retractedposition of each tactile pin of said tactile pins, and the movable unitmoves vertically while moving horizontally beyond the range in which theprojected or retracted positions of the tactile pins are controlled. 20.The tactile display apparatus according to claim 10, wherein thevertical movement mechanism of the movable unit comprises an actuatingmember which moves horizontally and integrally with the movable unit, afixed member which is fixed to the case body side of the tactile displayapparatus, and a one-way clutch mechanism which moves the movable unitvertically in association with interference of the actuating membermoving horizontally with the fixed member.
 21. The method according toclaim 14, wherein driving the movable unit comprises: moving the movableunit horizontally in a reciprocating manner; and moving the movable unitvertically a predetermined distance after each horizontal reciprocalmovement.